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State of UNITED STATES PATENT OFFICE;

CHESTER E. ANDREWS, F PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO THE SELDENCOMPANY, OF PITTSBURGH. PENNSYLVANIA, A CORPORATION OF DELAWARE.

PROCESS OF TREATING CYMENE.

No Drawing.

To all whom it may concern:

Be it known that I, CHESTER E. Annnnws, a citizen of the United States,residmg at Pittsburgh, in the county of Allegheny and, ennsylvania, haveinvented certain 'new and useful Improvements in Processes of TreatingQymene, of which the following is a s'pecificatlon.

The present invention relates to a process of treating cymene, and maybe employed in the treatment of cymene in a pure conditlon, or may beapplied to a crude cymene, and further involves the previous treatmentof materials containing cymene for the removal of some o f'the otheringredients. The inven tion provides a process of nitrating cymene,

' that is to say producing nitro-cymen'e, and

if desired the further treatment of the nitrocymene by reduction, toform amino-cymene,

which material is capable of use in the production of variousderivativessuitable for use in the arts.

As a starting material, I preferably employ the so-called spruceturpentine which known, producedas a by-product from the relief liquorin the production of wood pulp,

wood chips in sulfite liquor. The oily mais a product already by boilingspruce teriai so obtained in the treatment of spruce wood has been foundto contain very large a v amounts of cymene, althoughthe relief liquorproduct from other kinds of woods also containssome of this materiaL.The

, material is accordingly referred to under the term spruce turpentine,which term does not of. necessity mean that the material is exclusivelyobtained'from spruce, nor that the material is actually turpentine;

An analysis of a typical sample of spruce turpentinelshowed thismaterial to) contain cymene, terpenes, Water' and S0 in solution,.together with other materials which for-the;

purpose of the present invention may be disregarded.

he operation of the process is as The spruce turpentine is first treatedwith a quantity of quick lime, equivalent to a little more than thecombined water and S0 content, in order to precipitate calcium sul-'fite and calcium hydrate, and to some extent calcium sulfate due tooxidation of SO to S0,, after which the liquor is stirred, settled anddecanted or filtered or otherwise separated from the solid. The liquidre- Specification of Letters Patent.

Application filed September 13, 1917. Serial No. 191,245.

follows Patented Sept, 2, 1919.

ter mode pf operation is in most respects adv1sable,s1nce the terpenematerial, and most of the other impurities resent are found'not to bematerially altere during the nitration operation, and their presence inthe material does not produce any unfavorable effects, and apurification at a later stage of the process is more simple and morecomplete.

The nitration process is preferably carried out as follows. The cymeneor preferably the mixture of cymene'and terpenes is dissolved in asolvent. Sulfuric acid of 98% strength can be used as the solvent, inthe proportion of about 1 part of cymene by weight to 1 part of the acidby weight. In place of sul uric acid, other anhydrous solventswhicharenot capable of deleteriously affecting the nitration may be,employed, an example of such being glacial acetic acid,

" which. material can be used in the proportions of about one'andone-half arts of the acid to one part of cymene. his step 1spreferably'carried out while the mixture is cold. A mixture of sulfuricacid of 98% strength and nitric acid of. strength, preferably. in theproporations of "about 2 a parts of sulfuric to I of'nitric is thenadded to the solution of cymene insulfuric acid.

In the preferred fornrof operation, I dis solve 67 parts of the cymene(or preferably an amount of the purified spruce tur entine .containin 67arts of cymene) in 6 parts of sulfuric acid of about 98% strength.This'mixture is then cooled to about 0, C. A mixture of 105 parts of 98%sulfuric acid.

and 50 parts of 70% nitric acid is then made,

which mixture is then cooled to 0 C. The mixed acidsare run into themixture of cymene and sulfuric acid, while stirring and whilemaintaining the temperature throughout at about 0 C. It is necessary toprevent any extensive heating during the addition of the nitrating acid.The above amounts correspond to an excess of nitric acid of about 10%.The cymene is converted into mononitro-cymene, in a substantiallycomplete manner, and as soon as allof the mixed acid has been added, thereaction is substan- The oily mixture now contains as its prin cipalingredient l-meithyl-2-nitro-4-ispropylbenzene, V

The mono-nitro compound canbe purified if desired, by fractionaldistillation in a high V 'duce the sulfate of the. amin, inaqueousvacuum, say 28 inches or more. This however, is not necessary,and I refer toallow the purification to wait 1111121" a subsequentstage.

Themono-nltro-cymene is now preferably reduced tomono-amino cymene, byany suitable process of vigorous reduction, for which urpose'boiling themixture with powdered iron and hydrochloric acid is suitable, or anystrong acid-reducing agent may beeme ployed, or if desired the reductioncan be effected by treatment with hydrogen in the presence" of a nickelor similar catalyst.

The mono-amino-cymene can be distilled, for example by the introductionof a current of superheated steam,;to produce the relatively puremono-amino-cymene, which; latter may be employed for various purposes inthe p "As a more complete mode of purification, '7 the crude materialcontaining the mono; amino-cymene is agitated with a consider-' ablequantity of dilutesulfuric acid, to'prosolution; The sulfate is "a solidand is not volatile with steam. The impurities p-res ent, largelyterpenes, may be then removed from the solution by steam distillation,leaving' an-aqueoiis solution of the purified sulfate of the amin. 'Milkof lime or'other.

alkali is then added to the aqueous solution,4to decompose the sulfateand set; free the mono-amino compound, which is .an oilwh-ichis notsoluble in wateaa- The oil may a p v A 7 V ,purlties of an acid nature,removing the besteam-distilled from the mixture in a relatively purestate. I

Mono-amino-cymene'is suitable for use in" the production of variousdyestufi's and ther chemicals;

li'lel have I described the process "in great detail, I call attentionto the fact that the invention is not limited-v to the detailsreferred-to, but-variations in the process may be. made, withinthe scopeof the appended claims. 7

The strengths of acid and relative 1 proportions are thosefound to givethe'best com;

comprising cymene, terpenes, water and disabout 98% strength; adding thereaction amino cymene, and purifying the latter.

. terial containing cymene and terpenes in an anhydrous solvent, addingto the solution a 'acid, adding'to the solution a"'mixture of cymene hasbeen added, whereby the cymenemercial results. It will be noted however,

that the invention is not limited thereto.'

WhatI claim is: a V y 1. A process of treating a liquid material 0solved 80,, which comprises first adding an 7 amount of quick-lime atleast substantially sufficient to combine with all'of thewater and S0separating the precipitatefromthe liquid organic matter, dissolving theliquid 75 organic material in sulfuric acid of about- 98% strength, inthe proportions of 67 parts ofcymene to about 67 parts of sulfuric acid,cooling the mixture to about 0 C, adding to such cooled mixture, whileagitating and while maintaining therein a temperature of about 0 'C., amixture of about parts of HNO of about 70% strength and about 105 partsof H SO of mass to a large mass of water within a short time after theentire amount of mixed acidi has been added,- and separating the oilymaterial which contains mono-nitro-cymene,

reducing the mono-nitro-cymene to mono- 2. process of nltrating cymene,which compr ses dissolv ng spruce turpentine mamixture of strong nitricand sulfuric acid; while stirring and while maintainingjthe reactionmass at not materially above 0- C.,

until an amount of mixed acid has been" added suflicient to nitratesubstantially all of the cymene in the spruce turpentine.

, -3. A process of-nitrating cymene, which comprises dissolving amixture containing cymene and terpenes 1n strong sulfuric strong nitricand sulfuric acid whilestirrin and'whi-lel maintaining the reaction Imass at not materially above' 0 C., untilan amount of nitric' acidcorresponding" to ff an excess of about 10% over the amount 11 0 -1theoretically necessary to form mono '--nitr01- substantiallyunaffected. 1';

is 'nitrated and the other ingredients are 4. A- process of prod cingnitro a material which comprises treating spruce turpentine with analkali to neutralize im-' product of suchreaction, and subjecting the 7partially purified product containing cy- 126 I "mene andorganiclimpurities, to: nitration,

comprises dissolving. a jmaterial contain-fing terpenes and'containingabout 61 parts .of cymenein'iabout 67 parts of strong sul: furiic acid,adding thereto a-mixture'of about 1 parts-of strong sulfuric acid andabout 130 50 parts of strong nitric acid, while maintaining thetemperature of the reacting mixture at not above about 0 (1., and whilestirring the reacting mixture, whereby the cymene is nitrated and theother materials.

present are substantially unaffected.

6. A process of producing amino cymene which comprises nitrating thecymene in a 'crude material containing cymene and terpenes, thenreducing the nitro body in the mixture to an amino body, and separatingthe amino cymene from the'mixture.

7 A process of treating cymene material which comprises adding to spruceturpentine, an amount of quick-lime "sufiicient to unite with the waterand free acid therein, nitrating the cymene material, and reducing thenitro cymene in such material to amino cymene, and thereafter removingter" pene bodies therefrom.

8. Process of producing nitro cymene which comprises adding to sprucetur en-r tine, an amount of quick-lime at east equivalent to the waterand free acids-andacid anhydrids therein, separating the solid 1 10. Aprocess of producing amino cymene in a relatively pure state fromcrudespruce turpentine which comprises adding to the spruceturpentine'an amount of quick-lime at least sufficient to unite withallthewater and free acid and acid anhydrid therein, separating thesolids from the liquid, nitratre ucing the nitro cymene to amino cymene,and thereafter separating the ammo cymene from the mixture.

' 11. A process of treating crude spruce turpentine which comprisesadding lime,

filtering and nitrating the filtrate. In testimon whereof I afiix my sinature.

HESTER E. ANDR WS.

. in the cymene content of the liquid, then

